The data base which appears to provide the most consistent source of drug use data on youth and young adults is the National Survey co2nducted between 1971 and 1977. There are five studies in this series. The first two surveys were conducted for the National Commission on Marihuana and Drug Abuse. The most recent three were conducted for the National Institute on Drug Abuse. The five studies are entitled:

1. Public Attitudes Toward Marijuana

Description. The data from this 1971 survey were sought to provide a base from which policy-relevant information could be gathered. The study was planned to cover three aspects of the marijuana issue as well as selected other substances: (1) attitudes, feelings, and beliefs relative to marijuana and other substances, (2) knowledge of marijuana and other substances, and (3) the relationship between attitudes, beliefs, and behavior and certain explanatory variables.

Respondents and Sampling. A nationwide probability sample of youth (age 12-17) and adults (18 and older) was selected for this study and yielded 2,405 adults and 781 youth. The adult data were further subdivided into the following age categories for analysis: 18-25, 26-34, 35-49, and 50 and over. Young adults were considered to be particularly important for a drug use study; therefore, young adults aged 18-34 were oversampled and adults over age 35 were undersampled. The data were later weighted to compensate for this oversampling.

Drugs Investigated. Data were collected on the following drugs: alcohol, tobacco, marijuana, specific pills, cocaine, LSD, and heroin. However, the emphasis of the study was on marijuana, not on other drugs.

Information Collected. Three different types of instruments were used in this study:

A face-to-face structured interview for adults;

A self-administered questionnaire for adults to complete following the interview; and

A self-administered questionnaire as the only instrument for the youth sample.

The majority of questions in this study concerned attitudes and beliefs about marijuana and selected other drugs. However, several self-administered questions were asked about usage of various drugs. The self-administered questionnaire also gathered detailed information on the circumstances surrounding the respondents’ initial contact with and / or use of marijuana. Table “ 1971 Survey: Critical Questions Asked About Specific Drugs” depicts certain questions which could provide data on the prevalence and incidence of drug usage.

Data / Results

Among adults, age 18 and older, 15 percent reported using marijuana at some time. The comparable figure for youth, age 12-17, was 14 percent. Five percent of adults and 6 percent of the 12-17 age group classified themselves as present users.

Highest experience levels: 39 percent of young adults, 18-25; 44 percent of college students. There was a rapid falloff in reported usage after age 25.

Description. The 1972 survey drew heavily upon the earlier report (Public Attitudes Toward Marihuana) in forming questions and in providing background information about the drug abuse problem. As with the previous survey the majority of questions were asked during a personal interview, but some questions were self-administered.

Respondents and Sampling. The sampling strategy was the same as for the 1971 survey, with the exception that the sample was designed to oversample the 18-29 age group. The number of adults interviewed was 2,411, and the number of youth was 880.

Information Collected. The questions asked in this survey covered admitted drug behavior as well as attitudes and knowledge related to drugs. The usage of pills was covered in the face-to-face interview, while the usage of other drugs was covered in the self-administered questionnaire. Table “1972 Survey: Critical Questions Asked About Specific Drugs”, below, presents those questions which are critical to estimating the amount of youthful drug use and the specific drugs for which they were asked. Data on pills were included only when used for nonmedical reasons.

Data / Results

Overall reported experience with marijuana was about the same as in 1971, 16 percent of adults and 14 percent of young people had had experience with it.

Four percent of adults and 4 percent of youth used marijuana at least once a week.

Of all respondent characteristics, age was most markedly related to marijuana experience. Consumption peaked during ages 18-2 1. (55 percent of that group had had marijuana experience) and dropped off rapidly after that.

3. Public Experience with Psychoactive Substances

Description. The 1974 survey included some of the same questions asked in the earlier surveys, and at the same time expanded its coverage of patterns of drug use. As with the previous surveys, a combination of interviewer-administered and self-administered questionnaires was employed.

Respondents and Sampling. As with the previous surveys, the youth and adult respondents were selected on the basis of a nationwide probability sample. In this survey, a slightly larger age range (18-34) was oversampled compared to the oversampling of the 18-29 age range in the 1972 survey. The number of respondents interviewed in the adult category was 3,071 and the number of youths was 952.

Drugs Investigated. The following drugs were included in this survey: tobacco; alcohol; ethical and proprietary sedatives, tranquilizers and stimulants; marijuana; hashish; heroin; cocaine, methadone; LSD; and opium.

Information Collected. The data collection covered both attitude and drug behavior items. Sensitive behavioral questions were self-administered to increase the perceived anonymity of the response. Less threatening questions, including attitudes and some behaviors, were included in the questionnaire administered by the interviewer. The self-administered questions covered the patterns of drug use engaged in by the sample respondents. Certain of these questions are critical for estimating the amount of drug use occurring during that period. Table 5 “ 1974 Survey: Critical Questions Asked About Specific Drugs” presents a list of critical questions and the drugs about which they were asked. This table includes those drugs covered in the self-administered section as well as the interviewer-administered section.

Data / Results

The public had had more experience with marijuana than with any of the other psychoactive drugs studied. Nearly one adult in five (19 percent) and more than one young person in five (23 percent) reported ever having used marijuana. This represented a slight increase for the adult population, and a marked increase among the 12-17 age group.

Under half of the adults who had tried marijuana were current users (7 percent), while 12 percent of youth were current users.

Among the drugs studied, experience with psychotherapeutic drugs was next in incidence to marijuana, with 13 percent of the adult public and 10 percent of the young people reporting some nonmedical experience with an over-the-counter or prescription sedative, tranquilizer, or stimulant.

The use of marijuana, whether measured in terms of those who had ever tried it or those who were current users, showed strong age relationships. In each instance, people aged 18-25 formed the highest use cohort.

4. Nonmedical Use of Psychoactive Substances

Description. The 1976 survey consisted of two parts, a personal interview and a self-administered questionnaire. The study is sometimes referred to as the 1975-76 study.

Respondents and Sampling. The sampling procedure remained the same; however, those individuals in the 18-34 age group were oversampled because they were considered to be the most likely to provide drug use data. The number of adults interviewed was 2,590 and the number of youths was 986. An increased emphasis was placed on the 18-25 age grouping and all important data were presented for this group individually. Therefore, data are available on the following groups of individuals

Males / females 18-25;

Whites / nonwhites 18-25;

Not high school graduate / high school graduate / some college / not college graduate / college graduate / college student 18-25; and

Large metropolitan area / other metropolitan area / nonmetropolitan area 18-25.

Information Collected. The questions asked in this survey can be grouped into two categories factual or attitudinal questions, and behavior questions.

Table “1976 Survey: Critical Questions Asked About Drugs Used for Nonmedical Purposes” presents questions asked about use of specific drugs.

Data / Results

Among youth (12-17) more than one in five (22.4 percent) reported having used marijuana, and more than half of these (12.3 percent) reported current use, meaning in the past month. For adults (age 18 and over) the prevalence rate (21.3 percent ever used) was similar to that of youth, but adult current use rate was substantially lower at 8.0 percent.

Among the adult public, young adults between ages 18 and 25 had more experience with marijuana than older adults, age 26 and over. In fact, more than half the young adults had used marijuana while about one in eight older adults had used it. Those age 18 through 25 also had higher current use rates. Fully one in four in this age group were current users compared to one in twenty-five older adults.

5. National Survey on Drug Abuse: 1977

Description. The majority of the questions in the 1977 survey have remained the same from the previous year, to facilitate comparisons.

Respondents and Sampling. In this survey 1,272 youths and 3,322 adults were selected for the sample. The sampling procedure remained the same and included an oversampling of 18-25 year-olds.

Drugs Investigated. Alcohol; tobacco; proprietary sedatives, stimulants, and tranquilizers; methadone; heroin; opium; marijuana; cocaine; LSD or other hallucinogens; and glue or other inhalants were all investigated.

Information Collected. This survey included three types of questions: factual and attitudinal: nominative: and behavioral. The factual and attitudinal questions primarily covered familiarity with various drugs and opinions about marijuana.

The nominative technique was developed to provide additional information about heroin use. Since the reported levels of heroin use in a population are so small (.5 percent- 1.4 percent), it was considered necessary to gather as much information relative to heroin use from the sampled groups as possible. Therefore, in addition to asking the respondent directly about his or her own heroin use, he or she was asked to report on the heroin use (if any) of close friends.

As a partial cross-check on the heroin use data, the respondents were also asked to indicate how many of their friends knew for sure that they had used heroin.

The third type of data collected was behavioral. Table “1977 Survey: Critical Questions Asked About Specific Drugs” lists those questions which provide estimates of the amount of drug use which was occurring in the population.

Data / Results

More than one-fourth (28.2 percent) of youth (age 12-17) reported marijuana experience and about one-sixth (16.1 percent) reported current use (in past month). For adults (age 18 and over) the lifetime prevalence rate (24.5 percent) was somewhat lower than that of youth, and current use (8.2 percent) was half of that reported by 12-17 year-olds.

It is important to note that marijuana experience was strongly related to age and that the highest prevalence was found in 18-25 year-olds. Of this age group, six in ten had used marijuana, compared to fewer than two in ten adults 26 and over.

Young adults also reported greater lifetime prevalence in the use of hallucinogens, with 19.8 percent reporting use at some time as compared to 2.6 percent of older adults.

Use of a drug “stronger” than marijuana (and / or hashish) was reported by about one in four young adults, one in ten youth, and one in twenty-five older adults.

6. An Index of the Number of Drug Abusers in States and Major Urban Areas

Description. This study was conducted in 1975 based on the 1972 data collected for Drug Experience, Attitudes and Related Behavior Among Adolescents and Adults. The purpose of this study was to provide data on drug abuse for geographic units smaller than the whole U.S. The national surveys discussed earlier provide reasonably good estimates of the- number of abusers in the total U.S. population; however, the structure of the sampling plan does not allow for State-by-State estimates with the same level of precision. The procedure of the current study involved considering factors which were related to drug use (e.g., age, region of the country, education) and estimating the number of drug users in each State based on the number of individuals having had each of the critical characteristics.

Respondents and Sampling. The entire sample of adults (2,411) in the 1972 survey were used in this study. In addition, a subsample of 418 youth (12-17 years) were selected. This subsample represented all youth who were interviewed in a household where an adult also had been interviewed.

Drug Investigated. Marijuana, cocaine, heroin, hallucinogens, and volatile substances were investigated. These drugs were investigated individually as well as grouped as follows: one or more illegal substances; nonmedical use of ethical sedatives, tranquilizers, or stimulants; nonmedical use of one or more psychotropic drugs (sedatives, tranquilizers, stimulants); one or more illegal substances and / or medical use of psychotropic drugs.

Two risk factors were also included in this study: ever used and current use (within the past year).

Data / Results. A regression analysis was conducted to predict usage of specific drugs according to certain demographic and locational characteristics. Marijuana was the drug for which the constellation of characteristics predicted best. Roughly 27 percent of the variance in marijuana usage (ever used) was accounted for by the following variables: (age / education, sex, race / ethnic group, family income, community type, region, and percent of population in college dormitories). The strongest predictor appeared to be whether the individual was between 18-24 years old and a student. Usage of drugs other than marijuana was predicted much less successfully.

Once the regression coefficients had been calculated, it was a simple matter to apply them to specific State data, add up all of the weighted predictors, and adjust for State population to provide an estimate of State drug use.

Selections from the book: “Demographic Trends and Drug Abuse, 1980-1995”. Louise G. Richards, Ph.D. , ed. Estimates of probable extent and nature of nonmedical drug use, 1980-1995, based on age structure and other characteristics of U.S. population. National Institute on Drug Abuse Research Monograph 35, May 1981.